1. Field of the Invention
The present invention relates to a mobile communication system including a mobile communication terminal having an attached body that can be attachably and detachably attached to its main body, and devices used therefore. Particularly, the present invention relates to a mobile communication system in which it is possible to obtain various content data by exchanging attached bodies, and devices used therefore.
2. Description of the Related Art
Some types of mobile communication terminals such as mobile phone may attach an exchangeable panel for decoration to a part corresponding to the backside (exterior) of a liquid crystal display unit thereof. Manufacturers prepare such panels or attached bodies in a wide variety of types as options.
Japanese Patent Application Laid-Open No. HEI 4-117848 (1992) (document 1) has disclosed a mobile phone equipped with a protective cover for protecting the operation units such as ten-key board. In the case of the mobile phone described in this document, a function module that provides a function not provided by the mobile phone main body (for example, as a calculator, watch) is mounted on a protective cover, and the protective cover is made attachable to the main body. The technique described in document 1 provides the function not provided for the main body but provided for the protective cover.
Further, Japanese Patent Application Laid-Open No. 2004-221860 (document 2) has disclosed the use of an attached body in order to facilitate selection/setting of functions that a mobile terminal main body provides. An attached body described in document 2 holds identification information for identifying the attached body. When an attached body is attached, the mobile terminal main body reads the identification number of the attached body. Then, the mobile phone main body sets a functional operation mode specified by the identification number for itself. Thus, it is possible for a user to easily select/set a desired function provided to the main body without performing troublesome menu operation and button operation. Furthermore, since the contents of the function setting are indicated on the surface of the attached body, the user can learn the contents of the function setting immediately from its external appearance side.
However, these techniques only decorate the exterior of a mobile phone, protect the keypad, enable operation of a specific function by setting a key on the panel, or cause to set a specific function in accordance with the panel. Further, the mobile phone shown in document 2 only identifies the type of a panel and causes to set in accordance with the attached panel by combining the type of the panel and an arbitrary function. Furthermore, it is possible for the panel described in document 2 to perform the function even if it is attached to another mobile phone of the same type. Therefore, a person other than the purchaser of the panel such as one who has received the panel illegally or one who has duplicated the data stored in the panel to another panel can use the data stored in the panel. Because of this, for example, it is difficult for a person or company having the copyright of the music, picture data, etc., stored in the panel to avoid the risk of the unauthorized use of the works.